Housb electric



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WITNES ES:

ATTORNEY Patented Jan. 10, 1928.

HENRY L. EENNINGE. E F Sil PATENT till?" m. WA I HOUSE ELECTRIC 62; IKIANUFACTURING COMPANY, A CORZURATION F PENNSYL- VANIA.

GOVERNOR.

Application filed September 8, 1924. Serial l lo. 736,648.

My invention relates to governing apparatus. more particularly to that class of apparatus enugloyinp a fluid pressure, varying as a function of the speed of the machine governed. as the actuating medium, and has for its object the provision of apparatus of the character designated which shall be sim-- ple of construction, reliable in operation and shall. be readily adjustable for diii'crent operating conditions.

ln the applications of Henry F. Schmidt, Serial No. 580,3i'8, filed rluip'ust 7, 1922, il o. cornea. filed November 29, 1929., now lhrl'ent ididd/TGG dated April At, 1995, and T"i'.396. tiled Sept. l2, 1924:, now Patent hot-33,76? dated April 14-, all assigned hellestingrhouse l llectric and ldanutacluring; Company, there is described a ariable "fluid pressure vgovernor havingan ele ment actuated by the variable 'tluid pressure in UP'pUSll/lUn to the force exerted by a spring. lrleans are shown wherein a coin paratively wide range 0 5 governing inovement is Spflllf i attained. for a given deflection of the V and means are also shown for varying the comparatively wide range of. n1ovement aforesaid so as to provide a varying iron of opening of the adn'iission valve of he i) ole mover per unit oi? change in governing pressure.

The particular object o'l. my iuvci'ltion is to provide improved apparatus oi the eh: r- :irtcr i lezn-ribed in the a 'iplications aforesaid, simpler in design, easy to manufacture and rez ulily adjustable whereby itniay he adapted to widely varying conditions.

ilrpparatus embodying features of my invention is illustrated in the accompanying; drawings in which Fig. l. is a view, partly in section, SllOVv'lIlff my improved governing); apparatus applied to a steam turbine and li ies. Q 3, and t are detail views, drawn to a larger scale, ott parts of the apparatus.

lo the design of overnin4, apparatus wherein the force of variable fluid pressure is cnuiiloved to actuate an element in opposition to the force exerted by a spri g, ditliculties have been encountered due to the fact that a spring of sullicient strength to act in direct opposition to the variable fluid pressure, and ot the scale required to deflect sulllciently to provide ample governing movements is o't inordinate size and length, render ng its use in'ipractical. .lt has also been found desirable to provide a governing; apparatus for cont-rolling the adn'ussion valve to a steam driven prime mover wherein there is a constant rate of valve opening during a limited range of movement, and thereafter a varying rate of opening to compensate for the varving rate of new of steam through the valve at low ratios of pre sure between the inlet and exit sides there i At times when the pressure on the exit side of the admission valve is less than .57 off the ressure on the inlet side thereof, the steam flow through the valve ncreases directly with its opening area. ll heu the pressure on the exitside ot the valve increases beyond .5? of the pressure on the inlets-idc, the flow thereby does not ncrea e directly with the area of the opening an a relatively wider opening of the valve is necessary to secure a direct incre ment in the flow oitsteam thereby.

l1 accordance with my invention 1 provide a. variable fluid pressure governing;- apparatus having an element actuated by the fluid under pressure in opposition to the force er;- erted by a spring in which incorporated a simple follow-up mechanism providil'io; a comparatively wide range of movement oi the element for a. given deflection of the also provide means whereby, at

spring. .i. a predeteruiincd point. in the valve travel, its rate oi movement per unit of chan e in governing); pressure. and consequent unit of change in spring deflection may be varied. l acconuilish this by providing a supporting member for the spring, retain the supporting member from a stationary support at one side of the spring, and provide means niovable with the element for supporting the other side of the member.

Referring now to the drawings for a bet.- ter understanding); of my invention, I show in Fig. 1 a steam turbine havingan admission valve ll controlled by my improved governing apparatus at 12. The governing apparatus at 12 is actuated by fluid under pressure var zine with the speed of the p rime mover 10, developed by a. centrifugal pump til 13. driven by a shaft let of the turbine 10.

apparatus comprises a governor casing 18,

having a cylindrical upper portion defining an operating cylinder-19 in which an operating piston 21 is disposed. The operating piston 21 ishollow and is provided with tubular extensions 22 and 23 at itstop and bottom, respectively. 'The top extension is provided with a vent hole 25 so that fluid leaking into the upper portion may dram off. The operating piston 21 is provided with upper and lower admission ports 2 1 and 26 andan exhaust port 27 by means of which ports the governing fluidpressure may be admitted above or below the piston 21 to move it down or up in the cylinder 19, or tomaintain it stationaryx'as is well understood in the art to'which my invention relates.

The admission of fluid to the ports 24 and 26 is controlled by a tubular pilot valve 28, said pilot valve beingdisposed within the hollow portion of the piston 21 and being provided with suitable upper and lower ports 29 and 31. The pilot valve 28 is also provided on its outer surface with an exhaust passage 32, affording communication between either of the'pist-on ports 24: or 26 and the exhaust port 27. The pilot valve 28 is closed at its upper end by head member 33, which serves as the lower abutment for a spring; 3%. An upward movement of the pilot valve 28 places ports 31 and 26 in com munication, admitting fluid under pressure beneath the operatiiippiston 21 and places ports 2 1 and the exhaust cavity 32 and port 27 in communication exhausting fluid from above the operating piston 21 so that it moves upwardly, following the pilot valve. Upon downward movement of the pilot valve fluid under pressure is admitted above the piston 21 and fluid is exhausted from beneath the piston 21 so that it moves down wardly. Any movement of the pilot valve 28 is followed by an equal movement of the piston 21 until the ports 24.- and 26 are covered, when the piston 21 will remain stationary until another movement of the pilot valve 28 takes place.

' The operating piston 21 is provided at its upper end with an extended portion 36, to the upper end of which is attached a rod 37 for actuating the admission valve 11. Thespring 34 is located within the extended portion 36 and has an upper abutment 33 carried bva lever 39. The upper abutment 38 is provided with an adjusting nut 1-1 by means of which the compression of the spring; 341; may be varied and thus adjust the speed of the prime mover. The load on the spring; 34 is such that at normal load on the turbine. and consequent normal. speed and governing" pressure, it will pist withstand the pressure acting against the pilot valve 28.

abutment 33 will be hereinafter referred to r as lever arm or distance (6 while that part of the lever between the abutment 38 and the pivot -tl-2 will be hereimiftcr rclcrrcd to as lever arm or distance 7).

The support 4:1 is provided with a slot +10 and the fulcrum member 4-3 is provided with a threaded bolt 17, tittin into the slot 4-6 and having an adjusting nut, whcreb its position relative to the lever arm (a may be changed, either vertically or horizontally.

The fulcrum member 43 has a lint sui .1 arc 48 and a curved surface 51, which coincide at the edge 52 against which the lover arm bears during a limited range of movement of the operating piston 21. and limited 0])(11- ing of the admission valve 11. 'lhcrcnftci' it bears against the curved surface 51, in creasing the eiiective length of the lever arm (i upon downward movements of the operating piston, and decreasing; it upon upward movements of the operating piston. This serves to uiry the range of movement of the admission valve in a manner to be more fully described later.

The operation of the apparatus is as fol lows: Fluid under pressure varying with the speed of the turbine 10 is dcvclojn-d by the pump 13 and delivered to the governing apparatus 12 and to too interior of the pilot valve 28 throinrh the conduit ET. l pon an increase in speed. and conscqnciu ini-rmuc in governing; pressure, the force cxcricd h (he spring 3% is overcome and the pilot valve in is moved upwardly followed b v lhc ]Hl':Eiing piston 21 in a manner already described. As the pilot valve 21 moves lli)\-\'2li(il it further compresses the spring 34-, which compression is partly oii et by the lll lil'illtl n'iovcment of the open. gr piston 2i carry-- ing with it the end of the lover ifl at the pivot 42, thus permitting an upward movement of the movable abutment 3%. inasmuch as the other end of the lcvcr is hearing on the fixed fulcrnn'i 4.3, the movablc abutment 38 is held back by the lover and tho spring; 31-, compressed in the upward movement of the operating; piston. The extent of this upward movcn'scnt ol the piston. 21 per unit of deflection of thc spring 3': may be detern'iined by a consideration of the followin The pilot valve 23 and the piston 21 movcv intents upwardly until they assume their normal position relative to each other, that is, until the ports 2% and 26 are again covered. It will be clear that the pivot therefore moves upwardly the same distance as the pilot valve 28, and that the deflection of the spring Si is equal to the difference in inove merit of the abutment 38 and the pivot 4:2.

The movement of the pivot may now he determined by the simple law of the lever which states that each part of the lever moves a distance proportional to its distance from the fulcrum. Likewise, the difference in n'iovement of any two parts hears the same proportion to the difference of their distances from the fulcrum, which is their distance from each other. Applying this law, the movement of the pivot 42 is to the distance (6+ as the movement of the abutment is to the distance a. Also, the difference in movement of the pivot 42 and the abutment 38 to the difference of their distances from the fulcrum d3 (the distance 2)) is in the same proportion. Therefore the movement of the pivot 1-2 is to the difference of movement of the pivot 42 and the abutment i-ltl as the distance ct-l-o is to the distance i). in other wore. the moven'ient of the piston per unit of deflection of the spring 3 f is 21 the ratio of the distance (n+3) to the distance Z).

The movement of the piston 21 per unit of deflection of the spring 3% may he in creased by increasing the distance (6, since this increases the proportion n+7) to L; and it may be decreased by shortening the distance (L; which decreases the proportion 66+?) to b.

Assume for illustration, that lever arms or distances a and b are equal, in which case he distance w-l-b is twice the distance 6, and hat there an increase in governing pressure forcing;- the pilot valve upwardly causting a deflection of the spring 234i one unit; the piston 21, tlollowinp; the movements of the pilot valve 2, moves upwardly taking with it the pivot ll of the lever, until it has .ii'ioved or e unit more than the abutment 38. 'Jlhis difference of n'ioveinent provides for the one unit of deflection of the spring 34: iermitting the pilot valve 28 to resume its normal pos'iition relative to the piston 21 in which the ports and 26 are closed. The pivot 42 moves u 'iwaii'dly two units since the distance iii-r I) in this case is twice the distance Z). The movement of the piston 21 is therefore twice the deflection of the spring 53 i.

liv the adjustn'ient feature heretofore deid the length of the arm (t, and hence the relative lengths of the lever arms (t and i) may he varied, and the movement of the operating piston unit of deflection of "he spring 34: may be varied so to effect any desired governing moven'ient per unit of the spring; Pd

of deflection of the springill. increasing the length of the lever arm (4 increases the governing movement per unit of deflection and decreasing the length thereof decreases said movement. Fur-then more ralsine; or lowering; of the 't'ulcrum member to serves to adjust the speed of the machine governed. 7

Upon an increase in load, and a conscipie'nt decrease in speed of the turbine it) the n'essure developed by the pump 13 decreases and the force of the spring causes the pile velveilh to move dmvnwardly fol lowed by the operating piston 21 and the end of the lever at the pivot elih the action of the apparatus being; oppo ite to that just described for an upward movement of operating piston. During! a limited ranrre of movement of the operating piston 2i and limited opening of the arhnission valve ll. he lever arm (r, hea on the cd of the .ful ruin member the and the unit or name u deflection of the spring; 34- is eons Upon a further increase in load and c ent of the operating; piston Ell per ii iii; of taut.

orient decrease in s 'aeed, reouirii'uzj a ope-iii admission valve to of the direct increment in the stesun admitted to the turbine, the lever arm hears upon the curved surface Iii. of the can: fulrruni men-i her 4:23 in this position the lever z rin (t is lengthened, and a relatively movement of the operatir pistol) yer unit of deflection of the i) sp no at is effected.

l ly means of the ui'ljiistiugr holt i? the cam member 4:3 may be adjusted vertically and tl us adjust the point of opei'iing of the admission valve 11 when the lever be ins to hear on the cin'ved surface 5i oi cam member *3. Vertical adjustment of the cum member 4L8 would affect the speed of the prime mover, hut this eifeet may he neutralized by a counter adjustment of the adjustii'ig nut ll to n aintaiu the proper spriup; compressioni r urth r iloviuwai-i movement of the operating; piston :il i l l l the shove mentioned point results in lellfi in the arm a and mcreasingr the r- )Wllltl t of the operating piston per unit oi dei'iee tion of the spring 3%. This actioi should take place at that point when the or .re at the eXit side of the admission va 'e 11 is .57 of the pressure at the inlet side thereof. the prime mover requiring a further inci mentof stean'i thereto, the movement of the operating piston 2i and the ado, n1 valve ll is comparatively more per unit of define tion of the sgiiring"; 34-, and the area of open-- ing; of the :uln'iission valve made comparatively tif -cater in order to elfect a d rert increment of steam llow by the aiflinisiiou valve 11.

From the foregoing it will be apparent that I have invented an improved variahle Upon a further reduction indeed of.

tluid pressure governing apparatus, simple of design and operation, wherein a comparatively wide range of movement per unit of deflection in the spring element thereof is secured, and wherein awvarying rate ot opening; of the admission valve is obtained per unit of change in governing pressure.

lVhile I have shown my invention in but one term, it'will be obvious to those skilled in the art that it not so limited, but is susceptible of various other changes and modifications. without departing from the SPll'ltil'lBIGOf, and I desire. therefore, that only such limitations shall be placed thercupon as are imposed by the prior art or as are specifically set forth in the appended claims.

hat I claim is:

1. In a variable fluid pressure operated I governing apparatus, the combination of a pilot valve actuated by the variable fluid pressure, an operating piston controlled by the pilot valve and following its movements, a spring associated with the pilot valve for opposing the variable fluid pressure, a movable abutment tor the spring, a lever controlling the movable abutment, means carried by the operating piston supporting one end oi the lever, andmeane 'arried by a stationary member for supporting the opiosite end of the lever.

In a variable fluid pressure operated governing apparatus, the combination of a pilot valve actuated by the variable fluid pressure, an operating piston controlled by thepilot valve and following its movements, a spring associated with the pilot valve for opposing the variable fluid pressure, said spring being disposed between the pilot valve and a movable abutment, a lever controlling; the movable abutment, said lever bc-' ing disposed between a fulcrum carried by a stationary member and means carried by the operating piston, and means tor adjusting .u'iovements ot the movable abutment relative to the movements of the operating piston.

I 3. In a variablt-i fluid pressure operated govt-mung apparatus, the combination of an clcniieutactuated by the variable tluid pressure, a spring coacting at one end with the element for opposing the variable fluid pressure, a supportingmember coacting with theothcr end of the spring, means movable with the element "for IQtllIlJIlQ' the supportinn member at one side of the spring, and

stationary meanstor retaining the member 'endot the spring, a member supporting the abutment, means movable with the element essons for retaining the member at one side of the spring and stationary means for retaining the member at the opposite side.

5.111 a variable fluid pressure operated governilig apparatus, the con'lbination of an element actuated by the variable tluid pres sure, a spring coactinp; at one end with the element for opposing the variable fluid pressure, an abutment coacting with the other end ot the spring, a lever, means tor attaching the abutment to an intermediate point on the lever, a tixed fulcrum member for one end of the lever, and means movable with the element for SUPPOl'tlHQ the other end of the lever. 7'

(3. In a variable fluid n'cssurc operated governing ap] )aratus, the combination of a pilot valve actuated by the variable lluid pressure, an operating piston controlled by the pilot valve and ifOllOYv'iIlQ' its movements, a spring associated with the pilot valve and having one end secured thereto tor opposing the variable fluid n'essurc, an abutment tor the other end ot the spring, a lever tor supporting the abutment, means movable with the operating piston tor supporting one end of the lever, and a stationary member for supporting the other end.

T. In a variable :tluid pressure operated governing; apparatus, the combination of a pilot valve actuated by the variable tluid pressure, an operatingpiston controlled by the pilot valve and following; its movements, a. spring associated with the pilot valve and having one end secured thereto :tor opposing; the variable tluid pressure, a lever, an abutmentfor the other end ol the spring positioned midway between the ends oi the lever, means movable with the operating pi sten for supporting one end of the lover, a stationary member for supporting the other end of the lever, and means tor varying the relative lengths ot' the lever arms.

8. In a variable fluid pressure tmeratcd governing am aratus, the combination ol' :1 pilot valve actuated by the variable tluid n'essurc, an operating piston controlled by the pilot valve and following its movements, a spring; associated with the pilot valve and having one end secured thereto for opposing the variable fluid pressure, a lever, an abutment -for the other end ol the spring positioned midway between the ends ol' the lever, means movable with the operating piston for supporting one end ot the lover, a stationary member for supporting the other end of the lever, and means for *aryinp; the position of the stationary member.

In a variable fluid pressure operated governing apparatus, the cmnbination ot a pilot valve actuated by the variable fluid pressure, an operating piston controlled by the pilot valve and following its movements, a spring associated with the pilot valve and having one end secured thereto tor opposbill ltlll ill:

ing the variable fluid pressure, a lever, an abutment tor the other end of the spring positioned midway between the ends or the lever, means movable with the operating piston for supporting one end of the lever, a stationary member for supporting the other end oi? the lever, and means for varying the position of the aationary member longitudinally and laterally with respect to the spring.

10. ln a fluid pressure governing apparatus, the combination of an operating piston, an elcn'ient responsive to fluid pressure and having means controlling the movements oi: the operating iston, a :tulcrum member, a lever having one point movable with the operating piston and a second point held against movement by the tulcruln member, and a spring acting between said lever, at third point, and said pressure-responsivc clement, said second point oi the lever being at least twice as far from the first point as said third. point is :lirom said first point,

i 11. In a fluid pressure governing appara tus, the combination o'l an operating piston, an element responsive to lluid pressure and having means controlling the movements oi? the operating piston, a ttulcrul'n member, lever having one point n'uivable by the pis ton and a second. point held against move ment by the fulcrum member, and a spring acting between said lever, at a point intermediate the two first-mentioned points, and said pressureresponsive element, the pressure exerted by said spring on said pressureresponsive element being equal to the fluid pressure acting thereon.

12. In a fluid-pressure governing apparatus, the combination of an operating piston, a pilot valve controlling the admission of motive fluid to said operating piston, pre

sure-responsive means for actuating said til) a pilot valve control] pilot valve, a fulcrum member, a lever movable by the piston at -one point and held against movement by the fulcrum member at a second point, and a spring acting between a the lever, at a third. point, and the pressureresponsive element, said second point being spaced at least twice as tar from the first point as the third point is from said first point l3. in a fluid ru'ossurs governing appara tus, the combination oi an operating piston, A do the admission oi: motive fluid to said operating piston, pres-- sure-responsive means for actuating said. pilot valve, a fulcrum member, a lever mov able by the piston at one point and held against movement by the fulcrum member at a second point, and a spring acting be tween the lever, at a third point, and the pressureeresponsive element, said spring eaerting a lorce equal to the fluid pressure acting on said pressure responsive element,

14 lln a fluid-pressure governing apparatus, the combination of an operating piston, a pilot valve controlling the admission of motive liuid to said ope ating piston, a fulcrum member, a lever held against movemeat at one point by the fulcrum member and movable by the operating piston at another point, said pilot valve constituting a.

iluid iessure-iesponsive element, and a spring acting between the pilot valve and s:- d iever at a point intermediate the two :lirst-mentioned points, the pressure exerted by said saring on said pilot valve being equal to the fluid pressure acting thereon.

15. lo a fluid pressure governing apparatus, the combination of an operating piston having a hollow portion, a pilot valve disposed within the hollow portion and controlling the movements oli the piston, pressure-responsive means for actuating the pilot valve, a spring attached at one end to said. pressure-responsive means, and a lever for supporting the other end of the spring, said lever being movable with the operating piston at one side of the spring and held against movement at the opposite side of the spring.

16. In a fluid pressure governing apparatus, the combination of an operating piston, a statioi'iary element having a hollow portion in which. the piston operates, one of said elements having ports through which motive fluid is admitted to actuate the operating piston, a pilot valve controlling the flow or motive fluid through said ports, means responsive to fluid pressure and actuating the pilot valve, a lever movable at one point by the operating piston and held against move ment at another point by the stationary element, and a spring acting between the lever, at a third point, and the pressure-responsive means, said spring exerting a force on said pressureresponsive means equal to the fluid pressure acting thereon, and said third point being disposed near to that one of the two lirst-i'nentioned points of the lever which coacts with the element having the ports as to the other of said two points.

17. In a variable fluid pressure operated governing apparatus, the combination oi? a pilot valve actuated by the variable fluid pressure, an operating piston controlled by the pilot valve and following moveniients, a spring; associated with the pilot valve for opposig the variable fluid nessure, said spring being disposed between the pilot valve and movable abutment, a lever controlling the movable abutment, means carried by the operating piston supporting one end of said lever, and a lulcrum for the opposite end of said lever carried by a stationary member, said t'ulcrum permitting a varying relative rate of movement between the operating piston and the movable abutment.

l8. .ln a variable fluid pressure operated governing apparatus, the combination of a ill) ill)

pilot valve actuated by the variable fluid pressure, an operating piston controlled by the pilot valve and following its movements,

a spring associated with the pilot valve for opposing the *ariablo fluid pressure, said spring being disposed between the pilot valve and a movable abuti'nent, a lever controlling the movable abutment, one arm of said lever being carried by the operating piston, and a cam member :arried by a sta tionary element forming a fulcrum for the other arm ofsaid lever, said cam member having an angular edge and a curved surface the an ular ed 'e- "Jrovidin a substan- 7 2: o I h 'tially constant radius or movement for the lever arm during a limited range of movement of the operating piston and the curved surface thereafter varying the radius of moven'ie-n't.

19. In a variable fluid pressure operated governing apparatus, the combination of a pilot valve actuated by the variable fluid pressure, an operating piston controlled by having an angular edge and a curved surface,

the angular edge providing a substantially constant radius of movement for the lever arm during a limited range of movement of the operating piston and the curved surface thereafter varying the radius of, movement, and means for adjusting the position of said cam member so as to increase or decrease the substantially constant radius of movement of the lever arm.

' 20. In a variable fluid pressure operated governing apparatus,'the combination of a pilot valve actuated by the vz'niable fluid pressure, an operating piston controlled by the pilot valve and following its JUOYQD'ltlltS, a springassociated With the pilot valve for opposing the variable fluid pressure, said spring being disposed between the pilot valve and a movable abutment, a lever controlling the movable abutment, one arm of said lever being carried by the operating piston, a cam nicmbcr carried by a stationary elen'ient forming a fulcrum l'or the other arinof said lever, said cam member having an angular edge and a curved suri'acc, the angular edge providing a substantially constant radius of movement for the lever arm during a limited range of movemcnt of the operating piston and the curved surface thereafter varying the radius of movement of the lever arm, means for adjusting the position of said cam member so as to increase or decrease the substaiuiially constant radius of movement of the lever arm. and means for adjusting the position of said cam member so as to vary the length of said lever arm.

21. In a variable tluid pressure opemlml governing apparatus for a prime mover having an admission valve, the combination of a pilot *alve actuated by the variable .lluid pressure, an opm'ating piston controlling the opening and closing of the admission valve. said operating piston being controlled by the pilot valve and following its movements. a spring between the pilot valve and a movable abutment, a lever controlling the movable abutment, one arm of said lever being carried by the operating piston, a cam member supported by a stationary element formim a fulcrum for the other arm of said lever, said cam member having an angular edge and a curved surface, the ai'igular edge providing a substantially constant radius of movement for the lever arm during a limited rangc of movement of the operating piston and the curved surface thereafter varying the radius of the movement, means for adjusting the position of said cam member so as to increase or decrease the substantially constant radius of movement of the lever arm, means for adjusting the position of said cam member so as to increase or decrease the initial length of said lever arm, and means carried by the movable abutment for adjusting the COllllJltSSlOll of the spring.

In testimony \vlmrcol l have hcrcunto subscribed my name this second day ol' September, 1924.

HENRY L. JENNINGS.

ion 

